Rust 1.84 introduces strict provenance APIs

Rust 1.84 stabilizes the Minimum Supported Rust Version (MSRV) resolver, which favors dependency versions that are compatible with the stated project. MSRV. MSRV-aware version selection makes it easier for maintainers to maintain legacy toolchains by not having to manually select legacy versions for each dependency. Developers can enable an MSRV-enabled converter via .cargo/config.toml.

Also in Rust 1.84, the Rust compiler is in the process of switching to a new implementation of the feature solver. According to the Rust team, the next-generation feature solver is a reimplementation of a core component of the Rust type system and is responsible for checking that feature boundaries are respected. It is also used by other parts of the type system, such as normalization and type equation. In version 1.84, a new solver is used to check the consistency of a feature implementation, ensuring that there is at most one feature implementation for a given type. This fixes some theoretical problems with the old implementation’s correctness.

Rust 1.84 also stabilizes more than a dozen APIs. Rust 1.84 followed the release in late November. Rust 1.83which expanded the possibilities for running code in const contexts.